Decoration of graphene modified carbon paste electrode with flower-globular terbium hexacyanoferrate for nanomolar detection of rutin

Through a simple method, a new kind of flower-globular terbium hexacyanoferrate (TbHCF) particles was synthesized firstly, and then a flower-globular TbHCF/graphene (GR) modified carbon paste electrode (CPE) was fabricated. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), inductive coupled plasma emission spectrometer (ICP), scanning electron microscope (SEM) and electrochemical techniques were used to characterize the modified electrode. The electrochemical behavior of rutin on TbHCF/GR/CPE was studied. The electrochemical response of rutin at the TbHCF/GR/CPE was remarkable higher than that on the other modified CPE. Under the optimum determination conditions, TbHCF/GR/CPE provided rutin with a broader detection range of 1.0 × 10−10 mol/L-6.0 × 10−6 mol/L with a minimum detectable concentration of 0.04 nmol/L. This novel method was successfully used to determine rutin in pharmaceutical tablets.